Power shovels are in a category of excavation equipment used to remove large amounts of overburden and ore during a mining operation. One type of power shovel is known as a rope shovel. A rope shovel includes a boom, a dipper handle pivotally connected to a mid-point of the boom, and a shovel bucket (also known as a dipper) pivotally connected to one end of the dipper handle. Cables or wire ropes extend from a hoist drum over a pulley at a distal end of the boom to an end of the dipper handle supporting the dipper. The ropes are reeled in or spooled out by electric, hydraulic, and/or mechanical motors connected to the hoist drum to selectively raise and lower the dipper.
In most rope shovels, the ropes are connected to the hoist drum by way of anchors mounted to an outer surface of the drum. In particular, a cylindrical collar or ferrule is brazed to an end of each rope, the anchors are welded around their perimeters to the outer surface of the drum, and the ferrule of each rope is placed within a corresponding anchor. The ropes extend through the anchors to wrap tangentially around the drum. An exemplary hoist drum is disclosed in DE Patent 10 2005 004 0816 that issued to Schneider et al. on Aug. 10, 2006.
Although a typical hoist drum may be acceptable in some applications, the weld seams around the anchors can crack and fail in other applications. In addition, the tangential trajectories of the ropes at the anchors can allow the ropes to pivot relative to the drum, and pivoting of the ropes has been shown to cause premature wear. Finally, it may be possible in high-load applications for the drum to crush at the anchor sites and/or for welded seams at ends of the drum to crack. Because the welded seams are internal seams, they can be difficult to inspect or repair.
The internal hoist drum of the present disclosure solves one or more of the problems set forth above.